WASHINGTON (Reuters) - Critics of a plan for the U.S. government to cede control of the Internet's technical management to other countries might succeed in delaying such a move in Congress, a senior lawmaker said on Tuesday.

Senator John Thune, a senior Republican from South Dakota, told reporters lawmakers are "trying to work out ... what would be effective in terms of slowing this."

The U.S. Commerce Department oversees the Internet's management largely because it was invented in the United States.

Some Republican politicians, including Senator Ted Cruz of Texas, want to block the handover to global stakeholders, such as businesses, tech experts and public interest advocates.

Opponents of the transition said it could stifle online freedom by giving voting rights to authoritarian governments.

Tech companies, technical experts and academics have said the transition is overdue and necessary to keep the Internet open and globally oriented, and that the proposal includes safeguards against any potential abuse by any one country.

The plan to transfer oversight of the nonprofit Internet Corporation for Assigned Names and Numbers, or ICANN, is set to occur on Oct. 1, unless Congress votes to block the handover. The California-based corporation operates the database for domain names such as .com and .net and their corresponding numeric addresses that allow computers to connect.

The Obama administration approved the transition plan in June.

Thune said he would expect language delaying the change to be in a bill to fund the government starting Oct. 1. He expects congressional leaders to finish writing the bill next week.

Both houses of the Republican-controlled Congress would then have to vote on the bill and President Barack Obama, a Democrat, would have to sign it for it to become law.

A leading Senate Democrat, however, scoffed at the proposed Internet provision. "Can Ted Cruz and Republicans dream up any more obscure,irrelevant issues to stop the business of the American government?" asked Senator Dick Durbin of Illinois, the No. 2 Senate Democrat.

There are other outstanding government funding issues also being negotiated by lawmakers, including how much spending should be committed to fighting the Zika virus.